Score Echogenicity Fiber pattern/alignment Size of ligament 0 Anechoic area (central core lesion) Lacking of parallel pattern Acute injury (haemorrhage), 0-25% FA Enlarged width and thickness 1 Lesion site starting to fill with presence of hypo-echoic areas, and moderate diffuse decrease in echogenicity Lacking of nice parallel pattern, 0-25% FA Enlarged width and thickness 2 Lesion site gradually filling with presence of multiple areas with decreased echogenicity Increased parallel pattern, 25-50% FA Enlarged width and thickness 3 Demarcation between injured and uninjured tendon less distinct, Hypo-echoic areas are remaining Increased parallel pattern, 25-50% FA Mild enlarged width and thickness 4 Hardly any demarcation between injured and healthy tissue, Faint signs of hypo-echoic areas Close to total fiber alignment, 75-100% FA Almost no enlarged width and thickness 5 Echogenicity (almost) identical to contralateral ligament Close to total fiber alignment, 75-100% FA No enlarged width and thickness

Table 1: The scoring system used to evaluate and compare the ultrasound images in the present study. Different parameters such as echogenicity, fiber pattern/alignment (FA) grading, and size (width and thickness) of the ligament were considered and compared to the contralateral limb.